Paper manufacture



Patented May 8, 193 4 I umrao STATES PATENT OFFICE 1,957,474 PAPER MANUFACTURE Harold Robert was, Andover, Mala, assignor to Raffold Process Corporation, a corporation of Massachusetts No Drawing. Application July 8, 1932,

Serial No. 621,509 g 26 Claims. (01. 92-21) This invention relates to the manufacture of filler if, instead of using the above described waxy paper filled with alkaline filler. materials or mixtures of these with substantially The principal object of this invention is the water insoluble non-waxy material substantially employment in the manufacture of paper filled inert to alkaline filler which give a resultant ad- 5 with alkaline filler of substantially water insolube mixture of pasty or even liquid consistency, I em- 60 organic material of a non-waxy nature substanployby itself organic substantially water insoluble tially inert to alkaline filler, said material being non-'waxy material substantially inert to alkaline either of a pasty or liquid consistency. filler, which may vary from a pasty consistency by An important object is the use of such material imperceptible steps down to the liquid condition. to modify the characteristics of the paper in the I have found that such non-waxy material will 65 manufacture of which it is employed. in itself impart a certain degree of sizing to paper A further object is the use of such material to filled with alkaline filler in the absence of any produce a sized paper filled with alkaline filler. appreciable or substantial amount of waxy mate- A further object is to produce alkaline filled rial such as is described in my above referred to paper of especially high receptivity to printing patent, and where in the claims appended hereto 70 ink. I speak of non-waxy material or the like in the Other objects and advantages of the invenabsence of waxy material or the like, I intend tion will become apparent during the course of the phrase in the absence of to mean in the following description. the absence of any substantial amount of. I

In my Patent No. 1,819,441, granted August have found however that, for purposes of sizing, 75 18, 1931, I disclose paper filled with alkaline filler such non-waxy material of liquid consistency does and sized with waxy substantially water insoluble not appear to be so effective as such material of material substantially inert to alkaline filler, such pasty consistency, and of the 'pasty materials for example as paraflln or other hydrocarbon. I the stiffer pasty ones are more effective than the state that the paraflin employed may be of high softer pasty ones, but in general even the stiffer 80 or low melting point and that it may be fully pasty ones are not so effective as the waxy refined or may contain impurities, such for exmaterials previously disclosed. ample as oil. However, this relative inefllciency of sizing While at'room temperature fully refined parafquality compared with waxy material may be fin is a waxy solid, it will be apparent that the overcome in certain cases by the use of larger 3:, presence of pasty or liquid impurities, usually hyquantities of the non-waxy material in question, drocarbons, will produce an admixture of modified and incertain instances the cost of such macharacteristics which may vary by imperceptible terial in comparison with the cost of waxy madegrees from the waxy solid of fully refined parafterial makes it feasibleand sometimes economical fin through various pasty consistencies from a to use such non-waxy material. Furthermore, stiff paste to a softer paste and even down to a such non-waxy material may also in certain cases liquid, depending upon the kind and amount of be used advantageously where only a small degree impurities admixed with the paraflin. of sizing, say only from one to a few seconds In accordance with the disclosure in my above sizing test (as tested by flotation on aqueous ink),

40 referred to patent wherein, as stated, the use of is desired to be imparted to the resulting paper. impure as well as of pure waxy material is de- Also, its use seems to be advantageous in certain scribed, such admixtures have been found to give cases where practically no so-called sizing test a measure of sizing, the degree of which has been is wanted but where an enhanced receptivity to found in certain cases to be roughly proportional printing ink is desired to be imparted, which such 45 to the amount of waxy material present. material seems to possess the ability to impart.

Thus, where waxy material as above has been This is a characteristic of importance in paper employed in admixture with impurities it was be-' to be used for printing and particularly for color lieved that the waxy material alone was subwork on high speed presses. Paper made accordstantially responsible for the sizing effect iming to the present invention appears to possess 50 parted, and that the accompanying materials such greater receptivity to printing ink and thus acting as impurities were substantially without to produce clearer impressions with less tendency sizing or other beneficial efiect. a to offset thanthe alkaline filled papers hitherto I have foundhowever that under certain conmade, excepting perhaps those made with waxy ditions it is possible to attain a moderate degree .material'according to my prior process.

55 of success in sizing paper filled with alkaline My invention may be summarized as the process of including organic substantially water insoluble non-waxy material substantially inert to alkaline filler, of either pasty or liquid consistency, in paper filled with alkaline filler to impart to the paper so made certain characteristics, such as sizing of varying degree as desired, or greater printing ink receptivity with freedom from offset, or the like. Of course, it will be understood that the conjoint use in paper of such material with any substantial amount of waxy material is not novel because of the disclosure in my prior patent above referred to.

In the practice of my invention I may proceed by either of two modifications. I may either incorporate the non-waxy material into the paper mix before web formation or in the web during web formation, or I may apply it to the paper web subsequent to web formation.

According to the first modificationLmay intioduce in the beater (or other mixing device) with fibrous material and alkaline filler the nonwaxy material, preferably in emulsion form. The order of addition may be varied as desired. I may run this mix off on the paper machine with satisfactory results, but in general I prefer to employ a precipitant for the emulsion,. such as an acidic material, for example, alum.

With certain types of emulsions such as the substantially non-breakable or insoluble emulsifier type, I may dispense with a precipitant, as above, or may use an acidic material or metallic salt such as alum; but with this type of emulsion I sometimes find it convenient to employ two mutually precipitable materials such as rosin size and alum, or sodium silicate and acidic material, or the like, which act to concentrate the disperse phase of the emulsion upon the fibre. Such mutually precipitating materials may also be used with other types of emulsions if desired.

I may, generally with improved results, employ the "minimizing principle in connection with the first modification of my invention. This principle has been described in a number of my issued patents, and in its practical application consists briefly in substantially avoiding or minimizing the effect of alkaline filler on acidic material by adding one or more of the papermaking ingredients, such as alkaline filler, acidic material, material affected by alkaline filler, and the like, to the mix under conditions favoring the minimizing of the time and/or intimacy of contact of the constituents of the mix, e. g. at or subsequent to the point where. the fibrous mix is about to leave the last chest in the stock system,

commonly known as the machine chest, and prior fto the point of delivery of the mix to the webforming device. While the material may as stated be added at any point between the two indicated, I prefer to add the material at the mixing box, or at any point between the mixing box and the web-forming device, i. e. at the dilute stage of the papermaking operation.

The non-waxy material need not be added independently to the mix; It may be premixed with one or more of the other ingredients, e. g. alkaline filler, or with-part or all of the fibre, or with acidic material such as alum, in the presence of a colloid such as starch or colloidal clay, if desired, and while such premixed ingredients may be added in the beater or other point in the stock system, it is especially advantageous in certain cases to add them under conditions favoring the minimizing of the time and/or intimacy of contact of the constituents of the mix as described in detail above.

elevated temperature in the stock is advantageous,

if non-waxy" used.

If an emulsion be used I may prepare such an emulsion in a variety of known ways, a number of methods of preparing emulsions being dematerial of pasty consistency be scribed in my already issued patents. For example, I may use as an emulsifyng agent a saponified material such as a soap, for example ammonium oleate, or stearate, or rosin size, or the like, said saponified. material either being used as such or formed during emulsification; or gums such as gum ghatti, with dextrin if desired; or insoluble emulsifying agents such as clay, preferably colloidal clay, or two mutually precipitable materials producing an insoluble agent; or casein solution,'sodium silicate, or the like. Such meth-. ods of emulsification and others, as well as means for effecting them, are known in the art and are sufiiciently familiar or so readily available to the chemist, that further description is here unnecessary.

It is to be understood of course that there may be used conjointly in the manufacture of papers so made, other sizing or treating agents, such as rosin size and the like, either directly with the non-waxy material, or added separately. Starch is' especially useful in this connection.

As stated above, in this first modification of my invention I may if desired add the non-waxy material to the forming web on the web-forming device. The discussion above relative to condition in which the material is added, and ingredients added in connection therewith applies here with equal force. The application of the material is in general more diflicult at this point insofar as a Fourdrinier machine is concerned, owing to possible interference with sheet formation, but this difficulty is not so manifest with a cylinder machine. However, in general I prefer the addition to the fibrous mix rather than during web formation.

In the second modification of my invention I apply the non-waxy material to the already formed web either on the paper machine or later. For this purpose I may employ an emulsion of the .non-waxy material, with or without a precipitant, but I prefer a solution in an organic solvent, using if desired methods of application similar to those described in detail in my copending applications;

Serial No. 487,377, filed October 8, 1930, and Serial No. 609,555, filed May 5, 1932. Such methods comprise briefly the application to the paper web, either on the paper machine or later, of the nonwaxy material, preferably in solution form, by spray, trough, contact roll or the like, and in the case where a solution in an organic solvent is used the subsequent removal of the solvent by evaporation, suitably by heat-{which may in certain cases if desired be sufficient only substantially to supply the latent heat of evaporation of the solvent) or reduced pressure or both. In the'interest of economy suitable means for recovery of solvent may be provided.

If the solvent used is non-miscible with water,

able degree of opacity and which is suitable for printing or other purposes, and which is similar in appearance to, and by cursory observation is difiicult to distinguish from, ordinary clay-filled paper of the same grade. Such paper may be sized if desired or unsized, but possesses a special receptivity to printing ink. My paper is unlike and should not be confused with, papers saturated with oils or the like, and which are transparent or translucent, and in the claims the word paper is to be construed as being restricted to such papers as are not saturated with the pasty and/or liquid material specified.

As an illustrative example of the manufacture of sized paper by practicing my invention according to the first modification; I may use a furnish containing 1000 lbs. fibrous furnish, 250 lbs. alkaline filler, and 40 lbs. of the non-waxy material of pasty consistency, the same being in emulsion form, together with 40 lbs. of alum, the alum preferably being added at the dilute stage of the paper-making operation. As an illustrative example for the manufacture of a substantially unsized paper possessing a special receptivity to printing ink, I may substitute for the 40 lbs. of pasty material in the furnish above, 10 lbs. of non-waxy material of liquid consistency, the same being in emulsion form. Starch in an amount of 20 lbs. for example may be advantageously employed in either of the above furnishes.

As an illustrative example of the manufacture of sized paper by practicing my invention according to the second modification I may apply to a paper web containing alkaline filler a 5 per cent. solution of the non-waxy material of pasty consistency, the same being dissolved in petroleum ether. As an illustrative example of the manufacture of a substantially unsized paper possessing a special receptivity to printing ink, I may apply to a paper web containing alkaline filler a 2 per cent. solution of non-waxy material of liquid consistency, said material being dissolved in petroleum ether. In either of the above cases the web may advantageously contain starch.

It is to be understood thatthe above examples are to be taken as illustrative only and not as limiting, because, as will be apparent, I may carry out my invention with a wide variation as to materials, proportions, and conditions, and still obtain satisfactory results.

The word solid may be used to define two distinct characteristics of a substance. One characteristic is that which a substance possesses at any given temperature which makes it incapable, without the application of pressure, of spontaneously .or quickly changing its shape, at least when a small bulk of the substance say 25 cubic centimeters is being considered. The second characteristic that may be defined bythe term solid is that possessed by certain substances, of exhibiting substantial resistance to attempts at penetration.

Where I use the word pastyf herein I mean that the substance so characterized possesses solidity according to the first definition above but not according to the second. In other words, pasty substances are solid in that at ordinary or room temperature, when in small bulk, they .will not exhibit flow or will exhibit it only with extreme slowness, but on the other hand are sufficiently soft so that the finger with only slight pressure will penetrate the mass in a manner in which it will not penetrate a waxy material such as fully refined paraflin for example.

Where I use the word liquid herein, I mean that a substance so characterized will exhibit-" flow at ordinary or room temperature.

As will be apparent there is actually an imperceptible gradation possible between the pasty and liquid condition, but the above definitions will distinguish between them with sufficient accuracy for commercial purposes.

The organic substantially-water insoluble nonwaxy materials substantially-inert to alkaline filler and of pasty and liquid consistency which. are used in the practice of my invention may be derived from any' available source. Examples are hydrocarbons which may be derived, for example, from petroleum, shale, lignite, earth wax, or other natural or artificial source (whether animal, vegetable or mineral). Other examples are synthetic resinous products made, for example, by condensation. However, among those materials which I may use I do not intend to include such black or substantially black colored materials, which because of their color, are not feasible for use in white papers, or even in papers which are somewhat colored such as kraft or the like.

Where I use the word liquid herein in reference to non-waxy material or the like I mean to limit myself to liquids which do not have a vapor pressure sufiiciently high spontaneously to evaporate to a substantial degree at ordinary or room temperature, or at a temperature to which paper may be subjected in the .manufacturing process subsequent to the inclusion of such liquid either in the mix or in the paper web, as obviously the inclusion of any low boiling liquid would be of little or no avail owing to its substantial removal from the paper either spontaneously or by the heat to which the paper web containing such liquid was subjected.

In place of alum I may use other aluminum salts or other metallic salts such as zinc sulphate or the like, or other acidic materials such as acid, sodium bisulphate or the like.

By the term alkaline filler, I mean substantially water insoluble filler which when agitated in contact with freshly boiled distilled water, say for an hour, will impart a pH value to such water greater than 7.0, that is, which will be on the alkaline side of the neutral point. Among fillers included in this group may be mentioned calcium carbonate, of which lime mud from the causticizing process is one forin; calcium carbonate magnesium basic carbonate employed in' the paper disclosed in my United States Patent No. 1,595,- 416, issued August 10, 1926; calcium carbonate magnesium hydroxide disclosed in my United States Patent No. 1,415,391, issued May 9, 1932; and other substantially water insoluble normal or basic carbonates of alkaline earth metals (which expression is herein intended-to include magnesium), or compounds, double salts, or physically associated mixtures of these with one or more other acid soluble materials of a substantially water insoluble nature.

' the broad sense to include products of manufacture of all types and of all weights and thicknesses, which contain as an essential constituent a considerable amount of prepar d fibre and which are capable of being produced on a Fourdrinier, cylinder, or other forming, felting, shaping or molding machine.

When I speak of paper as having a special receptivity to printing ink" or greater printing ink receptivity or the like, I do not mean that said paper necessarily satisfies any one specific test such as rate of water or oil penetration or the like; but rather I mean broadly that, regardless of the result of any specific test performed on said paper, the paper so characterized possesses improved printing qualities.

The term fibrous mix or paper mix" as used herein is intended to mean a mix oi. various constituents including fibre from which paper may be made either directly or after the addition of other ingredients.

While I have described in detail the preferred embodiment of my invention, it is to be understood that the details of procedure, the propor-'- tion and kinds of ingredients, and the arrangement of steps may be widely varied without departing from the spirit of my invention or the scope or the subjoined claims.

I claim:

1. Filled paper comprising fibrous material, alkaline filler, and at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

2. Filled paper comprising fibrous material, alkaline filler comprising calcium carbonate, and

at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

3. Filled paper comprising fibrous material, alkaline filler comprising calcium carbonate and magnesium compound, and at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, in the absence of substantially water insoluble waxy organic material substantially inert to kaline filler, and non-waxy hydrocarbon of pasty consistencyin the absence of waxy hydrocarbon.

size, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

l0. Filled paper comprising fibrous material, alkaline filler, non-waxy hydrocarbon of pasty consistency, and size, in the absence of waxy hydrocarbon.

11. Filled paper comprising fibrous material, alkaline filler, nonwaxy hydrocarbon of liquid consistency, and size, in the absence of waxy hydrocarbon.

12. Filled ,paper comprising fibrous material, alkaline filler, at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, and precipitated size, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

l3. Filled paper comprising fibrous material, alkaline filler, at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pastyand liquid consistencies, and aluminum compound, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

l4. Filled paper comprising fibrous material, alkaline filler, at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, and starch, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

15. The steps in a process of manufacturing paper filled with alkaline filler, comprising mixing fibrous material, alkaline filler, and at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler, and running said mix oil" on a paper machine.

16. The steps in a process of manufacturing paper filled with alkaline filler, comprising mixing fibrous material, alkaline filler, at least one of a class of substantially water insoluble nonwaxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, and acidic material, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler, and running said mix off on a paper machine.

17. Thesteps in a process of manufacturing paper filled with alkaline filler, comprising mixing fibrous material, alkaline filler, at least one of a class'of substantially water insoluble nonwaxy' organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, and alum, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler, and running said mix ofi on a paper machine.

18. The steps in a-process of manufacturing paper filled with alkaline filler, comprising mixing fibrous material, alkaline filler, at least one of a class of substantially water insoluble nonwaxy organic materials substantially inert to alkaline-filler comprisingmaterials of pasty and liquid consistenciesand size,.in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler, and running said mix off on a paper machine.

'19. The steps in a process of manufacturing;

paper filled with alkaline filler, comprising mixing fibrous material, alkaline filler, at least one of a class of substantially water insoluble nonwaxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, size, and acidic material, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler, and running said mix off on a paper machine.

" 20. In a method of manufacturing paper filled with alkaline filler wherein material is added to a paper mix under conditions favoring the minimizing of the time-and/or intimacy of contact of the constituents of the mix, the'step of adding to said paper mix at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, in the absence of substantially water insoluble waxy organic material substan tially inert to alkaline filler.

21. In a method of manufacturing paper filled with alkaline filler wherein material is added to a paper mix under conditions favoring the minimizingof the time and/or intimacy of contact of the constituents of the mix, the step of adding to said paper mix at least one of a class of substantially water insoluble non-waxy organic materials of substantially inert to alkaline filler comprising materials of pasty and liquid consistences, and size, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

22. In a method of manufacturing paper filled with alkaline filler wherein material is added to a paper mix under conditions favoring the minimizing of the time and/or intimacy of contact of the constituents of the mix, the step of adding @VE/QW to said paper mix at least. oneoi' a class ofj sub-'- stantially water insoluble non-waxy organic mav terials substantially inert to alkaline fillercom-' prising materials of pasty 'and liquid cbnsistencies, size, and acidic material, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

23. In a method of manufacturingvpaper filled with alkaline filler' wherein material is added to a paper mix under'condi'tions favoring the minimizing of the time and/or intimacy of contact of the constituents of the the step vof adding to said paper mix at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler com-. prising materials of pasty and liquid consistencies, and precipitated size, in the absence of substantially water insoluble waxyorganic material substantially inert to alkaline filler. v

24. In amethod of manufacturing paper filled with alkaline filler wherein material is added to a paper mix under conditions favoring the minimizing of the time and/or intimacy of contact of the'constituents of the mix, the step of adding to said paper mix at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, and acidic material, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

25. In a method of manufacturing paper filled with alkaline filler wherein material is added to a paper mix under conditions favoring the minimizing of the time and/or intimacy of contact of the constituents of the mix, the step of adding to said paper mix at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies, and aluminum compound, in the absence of substantially water insoluble waxy with alkaline filler wherein material is added to a paper mix under conditions favoring the minimizingof the time and/or intimacy of contact of the constituents of the mix, the step of adding to said paper mix at least one of a class of substantially water insoluble non-waxy organic materials substantially inert to alkaline filler comprising materials of pasty and liquid consistencies,

and alum, in the absence of substantially water insoluble waxy organic material substantially inert to alkaline filler.

' HAROLD ROBERT RAFION.

CERTIFICATE OF CORRECTION.

Patent No. 1,957,474. May 8, 1934.

HAROLD ROBERT RAFTON.

It is hereby certified that error appears in the printed specification of the abovenumbered parent requiring correction as follows: Page 1, line 5, for "insolube read insoluble; page 3; line 142, for "1932" read 1922; page 5, line 48, claim 21, strike out the word "of"; and line 49, for "consistences" read consistencies; and that the said Letters Patent should he read with these correc tions therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 24th day of July, A. D.- 1934.

Bryan M. Battey (Seal) I Acting Commissioner of Patents. 

